This symptom sometimes occurs when a version of the eLicenser Control Center, more recent than the one contained in the virtual instrument installer, already is installed on your machine. This is easily resolvable:

Here is how to download your license:1. Update your eLicenser Control Center from <http://www.elicenser.net/en/latest_downloads.html>2. Launch the eLicenser Control Center3. Click on the "Enter Activation Code" button on the interface4. Enter the code ==> xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx-xxxx and click Next

MAC

To completely uninstall a program from a MAC computer please delete the following folders:/Library/Arturia/<instrument>/Library/Audio/Plug-Ins/VST/<instrument>.vst/Library/Audio/Plug-Ins/VST3/<instrument>.vst3/Library/Audio/Plug-Ins/Components/<instrument>.component